The victors of this cup contest will be in high spirits ahead of another encounter next weekend when the two sides face off in the third tier.
Match preview
After claiming an impressive 1-0 home win over Barnsley on the opening weekend of the new season, Plymouth suffered a 2-1 defeat away at Fleetwood Town on Saturday.
Ryan Hardie had put the Pilgrims in front with a 23rd-minute penalty kick, but the hosts turned the game on its head with goals either side of half time from Daniel Batty and Joe Garner, the latter netting an 88th-minute winner.
Steven Schumacher labelled his side's performance "average" at Highbury Stadium but believes they were unfortunate to come away from the match empty handed.
Plymouth now turn their attention to a double-header with Peterborough and will have fond memories of their last encounter against the Posh, as they secured an impressive 4-0 victory away from home in the first round of the EFL Cup in August of last season.
The Pilgrims have, however, lost their last two meetings with Peterborough at Home Park by an aggregate score of 8-1.
Peterborough are the only League One team to have won their opening two fixtures of the 2022-23 campaign after following up their 3-2 victory over Cheltenham Town with a 3-0 win at home to Morecambe last weekend.
Joe Ward and Ben Thompson put the Posh two goals in front at the break before a 72nd-minute strike from Hector Kyprianou secured a comfortable victory for Grant McCann's side.
McCann is pleased with his side's positive start to the new season but insists that they cannot take any game for granted, with back-to-back fixtures against Plymouth followed by a clash with Sheffield Wednesday next on the agenda.
Peterborough, who were relegated from the Championship last season, have been eliminated from the first round of the EFL Cup in each of the last five years and have only progressed as far as the fourth round once in nearly three decades.
The Posh do, however, head into Wednesday's game having lost only one of their last six competitive away matches and have also won four of their last five visits to Home Park.
Plymouth Argyle form (all competitions):
Peterborough United form (all competitions):
Team News
Plymouth boss Schumacher may be tempted to name the same starting lineup for the third successive game on Wednesday.
However, midfielder Jordan Houghton made his first appearance off the bench last weekend and will be hoping to force his way into the first XI ahead of either Matt Butcher or Adam Randell.
Schumacher is unable to call upon Conor Grant, Panutche Camara (both groin), James Bolton (foot) and Mickel Miller (thigh) due to injury.
As for Peterborough, Kwame Poku (calf), Dan Butler (ankle) and Oliver Norburn (knee) are all set to remain sidelined with injuries, while Harvey Cartwright is doubtful due to fitness issues.
Jack Taylor, Ben Thompson and Hector Kyprianou could all retain their places in centre-midfield, although Jeando Fuchs will be pushing to start after beginning last weekend's game on the bench.
Jonson Clarke-Harris, who scored a brace in Peterborough's opening away match of the new season at Cheltenham, is set to continue in attack alongside Jack Marriott.
Plymouth Argyle possible starting lineup:
Cooper; Wilson, Scarr, Gillesphey; Edwards, Butcher, Randall, Mumba; Azaz, Mayor; Hardie
Peterborough United possible starting lineup:
Bergstrom; Knight, Edwards, Kent; Ward, Taylor, Fuchs, Burrows; Thompson; Marriott, Clarke-Harris
We say: Plymouth Argyle 2-2 Peterborough United (Plymouth Argyle to win on penalties)
A closely-fought contest is set to be played out between two strong third-tier teams who will both fancy their chances of progressing to the next round.